Electrochemical sensors using oligonucleotides as recognition ligands for liquid biopsy in prostate cancer

In men, prostate cancer is the most frequently diagnosed malignancy worldwide. Early diagnosis improves its prognosis, with higher survival rates and a better quality of life for patients. However, diagnosis and characterization of tumors are mainly based on highly invasive tissue biopsies, with an incomplete representation of the entire tumor. In consequence, attention is turning to the so-called liquid biopsies, which provide molecular information about the tumor by detecting its specific components, including proteins, circulating nucleic acids or tumor cells, in bodily fluids such as blood or urine. Recent years have seen the development of a large number of electrochemical sensors employing oligonucleotides for the recognition of prostate tumor components in a minimal invasive way. Here we survey the reported designs, which are categorized as aptasensors and genosensors for the different molecular components identified as prostate cancer biomarkers. We present a critical evaluation of their analytical validity, identifying the challenges of bringing these devices to the clinical practice.